Rock Vegas Slot by Pragmatic Play

Forget the base game. Twenty paylines, nine symbols, no wilds, nothing happening between bonus triggers. There's no buy option to skip past the wait, either - three or more Bonus rocks on the grid is the only way into the Mega Hold and Spin round, where the reels blow out from their standard layout to a 10x10 field. A hundred positions, special reels spinning nothing but colored rocks and blanks against a neon-lit prehistoric backdrop.

Color placement is everything on that expanded grid. Rocks come in several tiers (green through gold), and when four matching rocks form a 2x2 cluster, they merge into a single larger rock with a 5x to 10x multiplier applied to their combined value. Push that to a 3x3 cluster and the multiplier jumps to between 35x and 500x. How many Bonus symbols triggered the round determines which rock colors appear at all. Five on the trigger spin strips out every low-tier color, leaving only orange, pink, and gold in the pool.

Then there's the key trail. Some rocks land carrying a key icon, and collected keys advance along a track toward locked chests. Each chest opens one of five outcomes: a direct payout between 10x and 500x bet, an individual rock value boosted by a 0.5x to 500x random factor, 4 to 10 extra keys pushed back into the trail, a retrigger that wipes the grid clean and restarts with fresh respins, or a general multiplier between 2x and 100x applied to your total win. And those general multipliers stack multiplicatively - two 5x awards from separate chests produce 25x, not 10x. Past the final chest sits a Mystery Multiplier node adding another 2x to 100x onto whatever you've already compounded. The trail loops with no cap on how many times you circle it.

A fire animation periodically drops extra rocks onto the grid between respins, padding the field without needing a natural hit. Retriggers from chests restart the round, but any general multiplier you've built carries forward. The whole payout is one calculation at the end: sum every rock value on the grid, multiply by the compounded general multiplier. A modest grid with a stacked 50x general multiplier outpays a full board sitting at 1x. Rock Vegas Mega Hold & Spin runs the same core system with updated dressing.